Process of manufacturing of leather.



G. CARR. PROCESS UF MANUFACTURING 0F LEATHER.

MPUCM'ION FILED NOV.6|1915.

Palntd June 19, 191".

6MM/kwam UNITED STATES PATENT OFFICE.

OMR GARR, F NEW YORK, N. Y.

Application filed November 6, 1915.

To allie/m, 'it 'may fonce-Tin.'

lie it known'that l. (Yuna a ritlzen ol' the United States ot America.and a resident ot' New York` bounty ot New vYorleaud State fracuuin`processes. the obfective is a nierelnent ot liquid within the hidefabric. induced h v boiling: the tanning' liquor in which the hide issalimenta-d1 under reduced preasure and at a temperature at which thehide substance is not deconilmsed. Huch inter cellular circulationdepends tor its 'activity upon the rigor oi" the. boiling, and it isdesirablc that the. hide and tanl'iinq'- liquor be so related that all'parts o'l the hide shall be at the saine tennuerature. M V inrention'relates to a intoeess oftl 'tanningr under reiluced pressure underconditions assuring equal `temperature over the whole spread of thehide.

ln the dra'wings- I Figuresl and 2 are views ot one forni ot apparatustor carrying out my improved method; and

Fig. 3 a vertical sectional yriew in diagram (it an apparatus torillustrating another way 'ot'earryiniir out my method.'

l overcome the above mentioned faults by removingV the hy(lrostiltiehead. Referring' to Figs. l and 2' of the drawing annexeih it will beseen that the liquor level (il) is at a` considerable distance below thestock (l). which is suspended from the sticks or supports (3). lt, now,the chamber pulled to a vacuum ot' 28, the `liquor below the level (2)lit-ought to 105", and by meansl ot a circulating pump A; on line(-i)the: liquor is sent through showers (D) over the stock74 the liquorwill cover the stock by spreadingr over it, but without'materialthickness. or hydrostatic head. Obviously the pressure is the saine,practically, upon all parts ot' the stock surfaceY1 and theboiling-point ot the intercellular *liquid sensibly lthe saine in allsueh palrta-the saine at the shank (G) as at the hack line `(7)Whieh isdistinctly not the caso Where the stock is hung submergediintlierliquor, with the-'levelv (2) ol the lat- 1 ter considerablyabove the. stock. It is tl'lerefore practically correct to say that ifthere be" vacuum of 28'inches in the, cham-ber,

Speci'cation of Letters Patent.

PROCESS OF MANUFACTURING OF LEATHER.

Patented June 19. 191 7.

Serial No.159927'.

the boiling-point of the intercellular liquidl is loir l". in y'allparts ot thehide.

lt in now apparent that the stock. hung in a chamber carryilreY aracuiini ot 2S inches. may be showered by the tanning' liquor atan.\"desired temperature without raising the tenn'aa'ature ot' theintercellulaiI liquid ahoral the boilihgI-point inrident to :2S inchesVac- `umn- -the heatV ol the liquor will fiasl1" out under the reducedpressure.'eausingr the intercellular liquid to boil and thus produce theintercellillar circulation desired. lvith this circulation operating',the liquor flooding' over the stock will be drawn il'n carrying'itatannin for absorption by the fiber.

`lt is practicable to brine the liquor t0 be showered over the stocktron] any sourcethe bottoni ot the chamber. troni a preceding chamber,or. troni an'exterior sourceand at an)y desired temperature. accordingro the racnnin eniiiloyed and condition of the Iiide liber as to theresistance to l1eat',.

Neither do l co'ntine in rsell" to showers lfor distributionorrirculatiim ot' the liquor over the. stoek'to obtain the absence ot'material hydrostatic. head. as auch distribution or cir culation may beseein-ed by various convenient means: as. 'tor example, the apparatusillustrated in Fig'. 3, where the stock is iin- Jnersed in the liquorwith level at 2. then hoisted (as shown in dotted lines) into theracuunl space, wherethe heat flashes out and -caiises the intercellularboilino-E the alternation ot iunnersion and hoisting beingr sutlicientto provide the absence of material hydrostatic head. Siii'iilarly. whereent-soles', blocks. .at-rips, etc` a re to be tanueththe stock may heplaced in shallow trays, the depth ot which wilhnot be sultieient tocreate an undesirable lrrdrostatichead aftew incl-ies of liquor notcausing' an undesirable range ot boiling-point. troni bottoni tosurface.

My process renders praeticalrle. the tan nale of thestock'on either thealkaline or acid side-that is theV limed and dehaired hide', linie plumpmag.7` beV tanned` ont in a tannin solution n'iade alkaline; a iterthetannage iseolnple'tcd the fabric may be'brought over to the acidside. by treatment in a fluid containing 'a suitable aidwlact-ie,butyric, acetic., ete. By such' manipula-tion theJ limeA "inthedehhaired hide may be ignored, and the usual need-for the neutralizing0f such lime, and. bringing of the stock to the 4acid plump condition,aroided; and the comdesired sections.

by my process', very great economy in hand- 'provide the 4 'plump toacid plump condition of the y :ben-ds, butts, etc., by 20 I pleted stockmay be brought out as plump as .the limed rstock from w ich'itfis tannedthe" practical importance of which' is very great. On such/Aalkaline-side stock, a waterproofing solution based upon waves, resins,caseinstc., soluble in alkali, may be conveniently, ed, the followingacid treatment assurinrr the fixation of such vmaterials Within theifabric, aswell as the bleaching of the surfaces. When the stock is to,be tanned on vthe acid-side, the composition of the i,tanning liquor maybe arranged to usual chan e from the lime iib such combination dependingupon the tanning material employed.l

proces's also renders practicable the manufacture of cut-soles, biocks,strips,

reversal of the conventional process of first tanning, finishing androlling the leather, and then cutting into the For this purpose, thehide in any state of preparation or partial tannage may be cut into thedesired sectionscut-sole, block, bend, etc.-and then tanned ling andtanning material, besides important improvements in quality, being obtained. l

I notv proceed with my process thus: The

Y prepared hide, at whatever stage of prepara-v ton, is placed in thevacuum chamber, vacuum pulled up, and the tanning liquor circulated oyerthe hide in such manner that there is no undesirable hydrostatic head,the liquor being atv any temperature desired, andbeing taken fromany-source desired.. LWhen the ta'nnage is@ complet-e, the stock maybefinished conveniently; or, the liquor may be Withdrawn and'afwater-prooiing solution run-in, vacuum maintained, and temperature ycarried high enou to boil-out the intercellular liquid; (if't e stockhas been tanned on the kaline side, the feci side? byl a suitable acidbath or treat nt, before or after Water-proofing). The stock is then'as'"dsired.

j' It will-be understood thatwhen prepared hide is referred toheein,'there is mea'nt hide 1n any state of-preparation-f-in the White,or plumped, or colored, fcut,

blgcked, or .in any state of preparation y "at which it maybe desired'tobegin thevuse of my process. Also, any-of the steps of my process maybeinterrupted or suspended for purposes of incidental manipulation-.as in-the production of split leathers, Where the .'hide, Vata:desired'stage'yof tannage, may be.

I sorntinn Siep being i'vidy removed from thelprocesfsfor splitting,`Yand the stock maybe withdrawal.l for bleaching,

if desired? or afbleaching 'step used.` Also',

maracas ning-liquore', .be

.intercellular circulation it may be brought to or the liquor may bewithdrawn for -nrich ment or alterationgor, several chalnlier may beconnected in a series, liquor being circu lated from one to another.lFurthermore, as the leather approaches complete tannage, it willwithstand higher temperature, and

such stage-of the absorption step may, it desired, be conducted athigherv temperature and lower. vacuum. v

I wish it understood also that it is not essential in all cases toheattlle main Ina-Ss or body of the tanning li uor to boiling point,since in some cases it ill be sufficient to bring the interior of thetank to a suiiiciently high temperature to boil or flash simply thethinner' liquor Within the fabric. In

fact, it is inipracticable to prescribe any definite temperature, asmany contingencies must be taken into account in determining thetemperaturel of the vacuum space. Neither is it completely essentialthat the `intercellular liquid should boil explosively,

as it may be merely agitated by the escape of the heat and so induceinward movement of the exterior liquor. .Intercellular movevment is theimportant thing, whether it be actual boiling or simple circulation dueto the heat curl-ents. Boiling 'would bring about a. more rapidcirculation, -but is not necessarily best in. all cases; for instance,young stock (with .much White fiber still in it) may do better with themilder circulation, while stockv already fairly tanned Y may need activeintercellular' boiling. The removalof the hydrostatic head expedites inbot-h cases and is,

therefore, the essential feature of my method.4

Having thus described my invention, whatlclaim is:

1. The process of tanning leather herein described, consistlng 1nmalntalninga partial vacuum 1n a tanning chamber containing the preparedhide vand a tanning liquor,

maintaining circulation of the liquor over' the hides withoutappreciable hydrostatic head thereon andheating the liquor suiciently tocause intercellular agitation and cons equent absorption of the tanninby the. hide. 2. The process of tanning` leather herein described,consisting in maintaining a partial vacuum in a tanning chambercontaining the prepared hide and' a tanning liquor, maintainingcirculation ofl the liquor over the hides Without appreciablehydrostatic head thereon, and heating the liquor sufiiciently to causeintercellular agitation and coisequent absorption of the tannin-'by thehie; .V

'3. The

described, consisting in maintaining .a paring the'prepared hidean'dfa'l-tai11j1i.ng\liquor,

process of tanningiileatherherein tial: vac'uum'infa tanningfchauibercontain- 1- i tation and consequent absorption of the tan-v the hidefwithout appreciable hydrostatic head thereon, heating the liquor' suiciently .to cause mt'ercellulari agitation and consequent absorptionof the tannin by the hide, circulating over the leather so produced andwhilethe same is still hot and wet a waterproofing solution until itsabsorption by `the leather, and then finishing the leather.

4. The process of tanning leather herein described, consisting inmaintaining apartial vacuum in a tanning chamber containing thepreparedhide and an alkaline tanning liquor, maintaining circulation of theliquor over thel hide without appreciableV vhydrostatic head thereon,and Y heating` the liquor sufficiently to 'cause intercellular agi- 1nin bythe hide.

he` process of tanning leather herein described, consisting inmaintaining a par'- tial vacuumgin a tanning chamber containthepreparedhide and an alkaline tanning liquor, maintaining circulation of theliquor over the hide without appreciable hydrostatichead thereon,heating the liquor sufficiently to cause intercellular agitation andconsequent absorption of the tannin by the hide, ,acidifying the leatherfabric so produced while the same is still wet and hot.

6. TheV process of tanning leather herein described, consisting inmaintaining a partial vacuum i'na tanning chamber containing the`prepared hide and an alkaline tantationand consequent absorption of thetan:-

nin bythe hide, acidifying the leathery ia rie sofproducedv whilethe-Sameiszst circulating, Hover vthe ,leather=wviilejthe still wet.and/hot a water-proofing sol tin---untl its absorption by the leather.n

.. tial vacuum iir a tanning chamber containing the prepared hide and analkaline tan- `ning liquor, maintaining circulation ofthe liquor overthe hide without appreciable hydrostatic head thereon, heating theliqubr autiiciently to cause intercellular agitation `and consequentabsorption of the tannin by fthe hide, acidifying the leather fabric soroduced while the same is still wet,fcireu ating over the leather whilethe same is still Wet and hot an alkaline water-proofing solution` untilits absorption by the leather.

8. The process of tanning leather herein described, consisting `inmaintaining a partial vacuum in a tanning chamber. containing theprepared hide and a tanning'liquor, maintaining circulation \of theliquor over es f circulating over the leather so produced while the sameis still wet a water-proofing solution until its absorption by theleather, acidifying the leatherwhile the same is still wet and hot.V

9. The process of tanning leather, herein described, consisting inmaintaining a partial vacuum in a tanning chamber `contain-VV ing the'prepared hide anda tanningliqiior,

maintainingciroulation ofthe liquor over the hide without appreciablehydrostatic headthereon, heating the liquor suiciently to cause.intercellular agitation and consequent absorption of the tannin by thehide,

circulating `over the leather so produced While the same is still wet analkaline 'waterroofing solution until its absorption 'by the eather,acidifying the leather while. the same is still wet and hot.

`sii

10,'The process of tanning leather herein I descm'bed, consisting inmaintaining a partial vacuum in a tanning chamber containing thepreparedhide, and an alkaline tan#` ning liquor, maintaining circulation of theliquor over the hide without appreciable hydrostatic head thereon,heating t e liquor suiciently to ycanse intercellular agitationy andconsequent"v absorption of th'e tanninby the hide, circulating over theleather'sopifd-l. duced while the samel is still wet an acid fwater-.proofing solution until its absorption by the leather.

ii. ,The placas' 0f tanning ieatheherein' c ,"ysisting in maintaining ap'arinf 'n aftanning chambercontain- ``repared hide, maintaining ajthin:layer of'liqiiid over the surfaces of ithe Vhide to thereby practicallyeliminate hydrostatic The process of tanning leather herein "described,consisting in maintaining a par-,

head, and heating the tanning liquor siiiiciently to cause intercellularagitation and consequent absorption ofthe tannin by the hide.

12.` The process of tanning. leather herein described, consisting inmaintaining a pai'- tial vacuum in a tanningchamber contain-` ing theprepared hide anda tanningliquor", v

es o

spraying the liquor unon the sui-fac the hide and thereby eliminatingall appreciable hydrostatic head, and heating the tanning liquorsiiiliciently to cause intercellular `agi tation and consequentabsorption of the tan-- nin bythe hide.

signature.

In testimony whereof I; hereunto aliix my OMA CARR.

